Paper-mill sludge composition



Patented May 8, 1928.

UNITED? STATES 1,668,961 PATENT OFFICE.

AUGUST E. HANSEN, OF NEW YORK, N. Y., AND ALBERT C. RUGER, OF 'WOLLASTON,

MASSACHUSETTS.

BAYER-MILL. SLUDGE oomrosrrrorr.

Drawing. Substitute for application Serial No. 521,771, filed December 12, 1921. This application fled May 27, 1928. Serial No. 112,171.

This invention relates to paper sludge compositions and more particularly to' such compositions containing rubber in its van- 1 ous forms. 5 In the manufacture of paper, and particularly inprocesses involving'the reclamation of old paper. there is produced a considerable bulk 'of material usually called sludge, which mixed with large quantitles H) of water, is allowed torun'oil from any or all of the mechanical equipment and tanks of paper mills.- In the prior art, this Watery sludge has been substantially a waste material, and accordingly has accumulated to such an extent that its disposition has become a serious problem. No commercial processes of utilizing this material have been found, so that in order to dispose of it, it has been allowed to accumulate in lagoons W or basins where the sludge proper settled out. In this way very large quantities of the sludge proper havebeen, and are being accumulated.

One of the objects of this invention is to utilize this paper mill sludge or equivalent material in desirable compositions of matter having wide use.

Other and further objects and advantages of this invention will appear from the more detailed description set forth below, it being understood that various changes may be made in this disclosure-by those skilled in the art, without departing from the spirit and scope of this invention.

In the utilization of this paper mill sludge, it may be employed of itself. or may be mixed with any of a number of binders or fillers. In such use.. the settled material 9218 ithas accumulated in the lagoons maybe 4 used without further treatment, although if desired it maybe purified as by washing or in any other desirable way. The material, either purified or not as desired. may then be compressed into a sheet or block, and

used as such.'or it may be used in powdered or shredded form.

Among the binders which have been found to be desirable additions when binders are used are the following: animal and vegebitumens, and their derivatives 6 and compounds; sil1cates;' and colloids. Shellac and similar materials may be used also.

table glues; waxes; gums; resins, either nat-' ural or artificial: rubber; hydrocarbons and As fillers, there may be any of the usual 5 mineral, vegetable, or animal fillers. and more particularly there are mentioned, cements, plaster of Paris, starch, etc, calcareo'us materials, silicates, etc. In giving these materials it is obvious that in some instances the binders may also act as fillers and vice versa. And further it will be apparent that :in these compositions, the paper sludge may be considered as the filler for the other materials with which'it is compounded: In compounding the paper mill sludge with the selected fillers or binders or both, any ordinary method of combining them may be employed. For example in mixing the rubber containing compositions it is desirable to use the usual milling machine wherein the rubber is placed upon one of a pair of heated rolls. and the sludge. either in powdered. shredded. or compressed form added thereto. In this way homogeneous products are easily obtained. The resulting rubber sludge compositions have many properties different from those of ordinary rubber.- and are therefore particularly adapted to a number of uses. For example the stretch of the composition is le s than that of ordinar rubber. and .the flexibility is alsolower. These compositions are therefore peculiarly adapted tothe manufacture of fabricated products such as boot heels and soles. steam hose. flooring. beltin and mechanical rubber goods of all descriptions.

In making these rubber containing compositions. rubberin any of its well known forms may be used. for example. latex. crude rubber. reclaimed rubber, rubber solution, and rubber gums such as caoutchouc. balata, andgutta percha. Since the sludge combines with the rubber very readily. it ma be used in widely varying proportions. The proportions used will determine to a large extent the hardness or resiliency of the re; sulting product. For example. a product containing 25 per cent of rubber and 75 per cent of paper sludge produces'a hard and stifi mixture. Increasing the proportion of rubber gives a softer product. For example a product containing 33 per cent too of rubber to 66 per cent of paper mill sludge, is soft. For most uses it will be desirable to use a proportion of about 25 per 1 cent of rubber to 75 per cent of paper mill sludge, and in order to avoid excessive brittleness on the one hand and extreme softness on the other, a proportion-l ing between and per cent of rubber ased on the other materials entering into the composition will be found to be satisfactory. However, other proportions may also be used, and for some purposes these proportions may be varied widely. Compositions containing from 25 to 75 per cent of rubber to from 75 to 25 per cent of paper mill sludge have proved advantageous.

Other examples'ot' compositions made in accordance with this invention are given below. For example, a product suitable for building board results from the use of the sludge material with plaster of Paris, being tougher and less brittle than'the latter used alone.

With ordinary glue the paper mill sludge gives a light, hard and tough product, while with sodium silicate, a similar material but not quite so hard is obtained. With both glue and sodium silicate, the sludge gives a tougher product than that obtained with either alone. Starch and sodium silicate with the paper mill sludge gives results similar to those obtained when using plaster of Paris alone. .Shellac on the other hand gives a .comparatively soft product with the sludge but one that is quite brittle. It will thus be seen that by combining these various materials with paper mill sludge in varying proportions, a product of any'desired characteristics can be obtained. Compositions in which shellac, plaster of Paris, sodium silicate, and glue are used as binders will give the best results when the proportion of the binder is the same as that sludge, or the equivalent of such sludge material. I

This application is filed as a substitute to application No. 521,771 by Hansen and Ruger, entitled Paper sludge composition, filed December 12, 1921. c

Having thus set forth our invention, we claim:

1. In a plastic composition, paper mill sludge as an essential component.

2. In a plastic composition, paper mill sludge as a filler.

-3. As an article of manufacture, a compressed block of paper mill sludge.

4. A plastic composition comprising paper mill sludge and rubber as a binder for the sludge.

5. A plastic composition comprising from 25 to 75 per cent of rubber and from 75 to 25 per cent of paper mill sludge.

6. A plastic composition comprising from 25 to 33 per cent of rubber and from 75 to 66% per cent of paper mill sludge.

7. As an article of manufacture, a fabricated. roduct containing paper mill sludge and ru ber.

8. As an article of manufacture, a boot sole containing paper mill sludge and rubber.

AUGUST E. HANSEN. ALBERT C. RUGER. 

